1. The Field of the Invention
The present invention relates generally to tools for installing bushings in vehicle transmissions. More particularly, it concerns a dual-sided, reversible tool for press-fitting a bushing into an annular cavity of a vehicle transmission at a predetermined depth therein.
2. The Background Art
Vehicle transmissions generally have lubricated, rotational cylindrical members which rotate within an annular cavity of a drum or some other type of housing structure. The rotational cylindrical member and the housing structure cooperatively define an annular passage therebetween. Lubricant is dispersed within such annular passages to maintain lubrication of the cylindrical members. It is known to install sealing rings over the cylindrical members to seal off at least portions of the annular passages to thereby channel the lubricant into a desired flow path. The life of the sealing rings is substantially increased with the use of bushings as known in the art.
A bushing is generally a solid metallic ring, commonly made from babbitt or copper. Bushings are typically press fitted into the annular cavity. The inner diameter of a bushing is narrowly tailored to match closely the outer diameter of the rotational cylindrical member after installation. One or more bushings slidably circumscribe thee cylindrical member to provide a rotational, bearing-type support and, perhaps more importantly, to maintain the cylindrical member in a lateral alignment. The bushings, in effect, prevent the cylindrical member from wobbling about and stretching and wearing against the sealing rings. Some bushings include lubrication slots in their interior surface to allow passage of lubricant between the bushing and the cylindrical member.
The necessity of bushings has motivated the development of various tools and methods for installation. It is known to install a bushing by placing it on the end of a steel cylindrical installer and pounding the cylinder with a hammer to press fit the bushing into an annular receiving cavity. However, this method is fraught with disadvantages. The hardness of steel installers causes damage to the bushing, and the ductility of the steel causes the installer to gradually deform from the pounding. In addition, the lack of resilience in steel inhibits transfer of impact energy from the hammer to the bushing, requiring more force and effort to install bushings.
It is time consuming and expensive to make bushing installers from steel, and thus more difficult to custom tailor the bushing installer to a specific bushing size. Moreover, the prior art installers known to applicant are not reversible and do not fit exactly every bushing. For example, the installers are usually manufactured to standard diameter sizes in one-inch increments. A user selects the installer which is closest to the size desired, rarely finding an optimal installer size for every bushing. The known steel installers are also of limited utility for installing other transmission apparatus.
It is important that bushings be installed to a certain depth within their annular receiving cavities. Improperly installed bushings have been known to block lubrication holes and interfere with the operation of thrust washers and other transmission apparatus. However, none of the prior art installers known to applicant have any depth control structure. Rather, they require the operator to use experience and perception to press fit a bushing to the proper depth within the annular receiving cavity. It is therefore a common occurrence for a mechanic to install a bushing too far into its annular receiving cavity, or not far enough. This requires additional time and energy to remove and/or reposition the bushing without damaging it using a steel installer.